Connection device for loudspeakers



Mar h1,1938. Q HSS 2,109,602

CONVECTION DEVICE FOR LOUDSPEAKERS Filed'Aug. 8, 1936 OUTPUT FROM POWER AMPLIFIER C STAGE \NVENTOR OTTO WE|SS ATTORNEY Patented Mar. 1, 1938 Otto Weiss, Berlin, Germ or to Teleany, assign iunken Gesellsehai't fiir Drahtlose Telegraphic m. b. 11., Berlin, Germany,

Germany a corporation 'of Germany August 16, 1935 Applicatgn August 8, 1936, Serial No. 95,043

6Claims.

In receivers with built-in loudspeaker it is desirable to provide a connection for an additional loudspeaker operating at a distance from the receiver. An especially simple possibility of switching will thereby be of advantage.

In accordance with the invention, at least two pairs of sockets are provided at the receiver, the one of which being connected to a. switch which when using this pair of sockets, disconnects the 10 loudspeaker ordinarily connected fler and built-in for instance in the radio appato the ampliratus.

Figure 1 shows the circuit. From one end of the secondary winding of the output transformer T a. line passes across the oscillatory coil 3 of the built-in loudspeaker, to the contact I of the switch i-2 of the connection device A. The other winding end of the transformer T is connected to the sockets 5 and 4 of the connection device, while a tap t of the transformer T is connected to the contact the sockets 3 and 6.

Now, if the second loudspeaker is connected between the contacts 5 and 6, both loudspeakers 2 of the switch and to receive current and are simultaneously operative.

When inserting the plug of the second loudspeaker into the sockets 3 and l, the said plug moves the pin 1 situated within the socket 3, whereby the switch i-2 will be opened, and

consequently, the built-in loudspeaker of the receiver will be disconnected and only the second,

or auxiliary loudspeaker, will be operative.

Figure 2 shows the structure of the connection device with the switch mounted thereon, and

Figure 2a shows diagrammatically the auxiliary loudspeaker and its associated double plug ill2. The two pairs of sockets 3-4 and 5-8 of the connection device serve for the selective insertion of the double plug ll-l2 of the second loudspeaker as explained above. The socket 3 has a lateral opening into which engages a nose 1 of metal or insulating material maintained in this position by means of a contact spring 0, and plate 9 fastened to said spring. The contact spring 8 is fixedly secured to the support iii. The actual contact I is pressed against the contact plate 2. by the spring I. .As soon as aplugis inserted into the socket 3, thenose 1- will be moved laterally,- thereby moving the plate 9 60 and spring 8 so that the switch contacts l-2 will be opened. 4

It will therefore be seen'that I have provided an arrangement for alternately operating either the speaker forming a part .of the receiving set.- 55 or an auxiliary speaker at a distance from the spective halves of the transformer secondary.

In the operation of one loudspeaker without the other, the operating loudspeaker is energized from the associated transformer secondary half, while the other half is open-circuited.

What I claim is:

1. The combination, in a radio receiver equipped with a loudspeaker, of an audio output transformer, circuit connections from said-transformer to the voice coil of said loudspeaker for energizing the same, said circuit connections including a normally-closed switch, an adapter provided with two pairs of sockets, both pairs being electrically associated with the output transformer, an auxiliary loudspeaker having a pair of terminal plugs capable of selective cooperation with either pair of adapter sockets whereby.

said auxiliary loudspeaker may be energized from the output transformer, and switch-opening means cooperating with a socket of one pair of cinity of thereceiver of an audio output transformer, circuit connections from said transformer to the voice coil of said loudspeaker for energizing the same, said circuit connections inciud-g'" ing a normally-closed switch, an adapter pro-" vided with two pairs of sockets, both pairs being electrically associated with the output transformer, an auxiliary loudspeaker adapted to belocated remotely from the receiver haying a pair of terminal plugs capable of selective cooperation with either pair of adapter sockets whereby said remote auxiliary loudspeaker may be ener-' gized from the output transformer, and switchopening means cooperating with a socket of one pair of sockets and with the normally-closed switch so that with the auxiliary loudspeaker plugged into the last mentioned pair of sockets, the receiver loudspeaker will be rendered inoperative, whereas with the auxiliary loudspeaker plugged into the other pair of sockets, both loudspeakers will be rendered operative simultaneously.

3. A circuit arrangement for utilizing an aux iliary loudspeakerin conjunction .with a radio receiver having a normally-equipped loudspeaker -wl ereby said loudspeakers may be selectively in a radio receiverequipped with a loudspeaker located in the vi-,

operated, either one without the other or both simultaneously, comprising an adapter having two pairs of sockets, an audio output transformer having a center-tapped secondary, two of the sockets, one of each pair, being electrically connected together and to one end of the transformer secondary, the two remaining sockets being electrically connected together and to the center-tap of said secondary, circuit connections between the center-tap of the secondary and the other end of the secondary for energizing the normally-equipped loudspeaker, said last mentioned circuit connections including a normally-closed switch, and switch-opening means cooperating with one of the adapter sockets, the arrangement being such that without the auxiliary loudspeaker being plugged into the adapter socket only the normally-equipped loudspeaker will be operative, whereas with the auxiliary loudspeaker plugged into that pair of sockets having the switch-opening means cooperate with one of the sockets, only the auxiliary loudspeaker will be operative, and with the auxiliary loudspeaker plugged into the other pair of sockets, both loudspeakers will be operative simultaneously.

4. A circuit arrangement for utilizing an auxiliary remotely-located loudspeaker in conjunction with a radio receiver having a normallyequipped loudspeaker whereby said loudspeakers may be selectively operated, either one without the other or both simultaneously, comprising an adapter having two pairs of sockets, an audio output transformer having a center-tapped secondary, two of the sockets, one of each pair, be-

ing electrically connected together and to one end of the transformer secondary, the two remaining sockets being electrically connected together and to the center-tap of said secondary, circuit connections between the center-tap of the secondary and the other end of the secondary for energizing the normally-equipped loudspeaker, said last mentioned circuit connections including a normally-closed switch, and switchopening means cooperating with one of the adaptarcaeoa er sockets, the arrangement being such that without the auxiliary remotely-located loudspeaker being plugged into the adapter socket only the normally-equipped loudspeaker will be operative, whereas with the auxiliary remotelocated loudspeaker plugged into that pair of sockets having the switch-opening means cooperate with one of the sockets, only the auxiliary loudspeaker will be operative, and with the auxiliary loudspeaker plugged into the other pair of sockets, both loudspeakers will be operative simultaneously.

5. In combination, an audio output transformer having two secondaries, a loudspeaker energized from one of said secondaries and having in its connections thereto normally-closed switch contacts, the other of said secondaries adapted to energize a second loudspeaker, and means whereby connection of said second loudspeaker into operative relation with its associated secondary causes the opening of the switch contacts associated with the first mentioned loudspeaker.

6. In combination, an audio output transformer having two serially-connected secondaries, a pair of sockets having electrical connection respectively to one end of one of said secondaries and to the common ends of both secondaries, a second pair of sockets, each having an electrical connection to one of the sockets of the first pair, the uncommon end of the second secondary having a connection to the common ends of the secondaries, said latter connection including the voice coil of a loudspeaker and normally-closed switch contacts, and a second loudspeaker having associated with its voice coil a pair of plugs, which when inserted into the first pair of sockets causes the energization of the latter loudspeaker simultaneously with that of the first loudspeaker and when inserted into the second pair of sockets causesthe energization of the latter loudspeaker and the deenergization oi the first loudspeaker by the opening of the normally-closed switch contacts. 

